package com.dylan.channel.v4;

import java.util.Objects;
import java.util.Queue;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.logging.Logger;

public abstract class SingleThreadEventExecutor implements EventExecutor {
    Logger logger=Logger.getLogger(SingleThreadEventExecutor.class.getName());
    Thread thread;

    Queue<Runnable> taskQueue;

    public SingleThreadEventExecutor() {
        taskQueue=new LinkedBlockingQueue<>(1024);
    }

    @Override
    public void execute(Runnable command) {
            if(null==command){
               logger.warning("任务不能为空!");
                return;
            }
            //将任务添加到任务队列
            if(!addTask(command)){
                //TODO 执行拒绝策略
            }

            //启动线程完成任务
            startThread();
    }

    private void startThread() {
        if(thread!=null){
            return;
        }
            new Thread(()->{
                thread=Thread.currentThread();
                SingleThreadEventExecutor.this.run();
            }).start();
    }

    protected abstract void run() ;

    protected void runAllTask() {
        Runnable task = taskQueue.poll();
        if(Objects.isNull(task)){
            return;
        }
        for (;;){
            task.run();
            task = taskQueue.poll();
            if(Objects.isNull(task)){
                return;
            }
        }
    }

    protected boolean hasTask() {
        return !taskQueue.isEmpty();
    }

    private boolean addTask(Runnable command) {
        if(Objects.isNull(command)){
            logger.warning("任务不能为空!");
           throw new RuntimeException("任务不能为空!");
        }
        return taskQueue.offer(command);
    }

    @Override
    public void shutdownGraceFull() {

    }

}
